Method for producing a monocrystalline layer of lithium niobate by transferring a seed layer of yttria-stabilized zirconia to a silicon carrier substrate and epitaxially growing the monocrystalline layer of lithium niobate and substrate for epitaxial growth of a monocrystalline layer of lithium niobate

Abstract

A process for producing a monocrystalline layer of LNO material comprises the transfer of a monocrystalline seed layer of YSZ material to a carrier substrate of silicon material followed by epitaxial growth of the monocrystalline layer of LNO material.

The invention claimed is: 
     
       1. A process for producing a monocrystalline layer of lithium niobate (LNO) material, comprising:
 joining two silicon wafers to form a carrier substrate of silicon defining a detachable interface within the carrier substrate of silicon, the detachable interface including a joint between the two silicon wafers including one surface of the two silicon wafers that is roughened; 
 transferring a monocrystalline seed layer of yttria-stabilized zirconia (YSZ) material directly onto the carrier substrate of silicon including joining a monocrystalline substrate of YSZ material to the carrier substrate of silicon; and 
 epitaxially growing the monocrystalline layer of LNO material on the monocrystalline seed layer of YSZ material, 
 wherein the joining the monocrystalline substrate of YSZ material to the carrier substrate of silicon comprises molecular adhesion of the monocrystalline substrate of YSZ material to the carrier substrate of silicon, the molecular adhesion including bonding the monocrystalline substrate of YSZ material to the carrier substrate of silicon at ambient temperature and annealing a bonding interface between the monocrystalline substrate of YSZ material and the carrier substrate of silicon to consolidate the bonding interface. 
 
     
     
       2. The process of  claim 1 , wherein the monocrystalline seed layer has a thickness of less than 10 μm. 
     
     
       3. The process of  claim 2 , wherein the joining the monocrystalline substrate of YSZ material to the carrier substrate is followed by thinning the monocrystalline substrate of YSZ material. 
     
     
       4. The process of  claim 3 , wherein the thinning comprises forming a weakened zone delimiting a portion of the monocrystalline substrate of YSZ material to be transferred to the carrier substrate of silicon. 
     
     
       5. The process of  claim 4 , wherein the formation of the weakened zone comprises implanting atomic and/or ionic species into the monocrystalline substrate of YSZ material. 
     
     
       6. The process of  claim 4 , wherein the thinning comprises detaching at the weakened zone so as to transfer the portion of the monocrystalline substrate of YSZ material to the carrier substrate of silicon. 
     
     
       7. The process of  claim 3 , wherein the monocrystalline seed layer of YSZ material is in the form of a plurality of tiles each transferred to the carrier substrate of silicon. 
     
     
       8. The process of  claim 3 , wherein the detachable interface is configured to be detached by a laser debonding technique and/or chemical attack and/or by application of mechanical stress. 
     
     
       9. The process of  claim 1 , wherein the monocrystalline seed layer has a thickness of less than 2 μm. 
     
     
       10. The process of  claim 1 , wherein the monocrystalline seed layer has a thickness of less than 0.2 μm. 
     
     
       11. The process of  claim 1 , wherein the transfer of the monocrystalline seed layer of YSZ material to the carrier substrate of silicon comprises joining a monocrystalline substrate of YSZ material to the carrier substrate, followed by thinning the monocrystalline substrate of YSZ material. 
     
     
       12. The process of  claim 6 , wherein detaching at the weakened zone so as to transfer the portion of the monocrystalline substrate of YSZ material to the carrier substrate of silicon comprises application of a thermal and/or mechanical stress to the monocrystalline substrate of YSZ material. 
     
     
       13. The process of  claim 1 , wherein the monocrystalline seed layer of YSZ material is in the form of a plurality of tiles each transferred to the carrier substrate of silicon. 
     
     
       14. The process of  claim 1 , wherein the detachable interface is configured to be detached by a laser debonding technique and/or chemical attack and/or by application of mechanical stress. 
     
     
       15. The process of  claim 1 , wherein the annealing is performed at a high temperature up to 1100° C. 
     
     
       16. A substrate for epitaxial growth of a monocrystalline layer of lithium niobate (LNO) material, comprising;
 a monocrystalline seed layer of yttria-stabilized zirconia (YSZ) material directly on a carrier substrate of silicon; and 
 wherein the carrier substrate of silicon comprises two silicon wafers joined together defining a detachable interface, the detachable interface including a joint between the two silicon wafers including one surface of the two silicon wafers that is roughened. 
 
     
     
       17. The substrate of  claim 16 , wherein the monocrystalline seed layer of YSZ material is present in the form of a plurality of tiles. 
     
     
       18. The substrate of  claim 16 , wherein the detachable interface is configured to be detached by a laser debonding technique and/or chemical attack and/or by application of mechanical stress.